Unanswered: Eclipse + Phonegap ==> ajax call to local webserver

I have installed xampp and mysql on my windows pc. I use sencha touch 1.x. I have a website running locally. It is under "htdocs/website". It runs perfectly ;-)
I have developped a mobile app (it is under "htdocs/mobile"). I tested the app first with google chrome. In the app there are some ajax calls to the local webserver (e.g. login of user). This works perfectly. I can send a request and I receive a response.
I use the "Ext.util.JSONP.request" to call webservices.
Now I installed eclipse, phonegap and ADT, created a new android project in eclipse. I start my local webserver and run my app in eclipse as an android application.
I get no errors. Android simulator is started and the app opens. But when I make a call to my webserver nothing happens.
What is wrong?
thanks